Rotary finishing machine having removable screen panels

ABSTRACT

IN A ROTARY FINISHING MACHINE OF THE TYPE COMPRISING A ROTATABLE BOWL ADAPTED TO CONTAIN A MASS OF ABRASIVE FINISHING MEDIA, A PLURALITY OF REMOVABLE SCREEN PANELS ARE USED TO COVER SCREEN OPENINGS IN THE LATERAL WALL OF THE BOWL. THE SCREEN PANELS MAY BE REMOVED FOR CLEANING. SELECTION IS PERMITTED AMONG SCREEN PANELS HAVING PERFORATIONS OF VARIOUS SIZES ACCORDING TO THE SIZE AND TYPE OF ABRASIVE FINISHING MEDIA TO BE USED IN A GIVEN MACHINE OPERATION.

A. K. FERRARA 3,570,184

ROTARY FINISHING MACHINE HAVING REMOVABLE SCREEN PANELS Filed Feb. 19, 1969 4 I 0 2 w ,0 w u w 00 MM 0 0 M 0 w W 0 0... m

March 16, 1971 2 0 j 2 8 j w J 0 0 0 I m d f I O O O O lb 1 n I 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ILL J 9U w 000 0 000 00 1 0 0000000 O 0 0 0 0 A? 0 0 0 0 0 0 0 0 0 0 o e 0 0 0 0 0 0 M 0 0 0 0 0 0 \\\\-\\.\\\\.\-\\-Lfi1iaux-aiml- EH u 0 0 0 0 0 0 0 0 O O O O O 0 fl j United States Patent 3,570,184 ROTARY FINISHING MACHINE HAVING REMOVABLE SCREEN PANELS Achille K. Ferrara, Addison, I]l., assignor to Ultramatic Equipment (10., Addison, Ill. Filed Feb. 19, 1969, Ser. No. 800,387 Int. Cl. B24b 19/00, 31/02 US. Cl. 51-7 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION This invention relates to improvements in a rotary finishing machine of the type comprising a rotatable bowl adapted to contain a mass of abrasive finishing media, means for rotating the bowl, and means for turning work pieces in the path of the mass of abrasive finishing media.

Machines of this type have wide industrial application for deburring, cleaning, polishing and the like. Abrasive finishing media used in these diverse operations is uniformly classified by size and type and may range from fine grits for use in polishing to heavy chips for use in heavy deburring. Abrasive finishing media may be formed of limestone or other natural materials or may be formed of a manufactured ceramic-based or plastic-based material. Abrasive finishing media formed of any of these materials fragment in use, producing abrasive fines.

The bowl of a conventional machine of this type comprises a generally cylindrical wall and a generally circular bottom integral with the wall. -In at least a lower portion of the wall, a multiplicity of uniform perforations are provided. Provision is made to externally wrap the perforated portion of the wall with screen cloth which then is held in place with steel straps or other suitable holding devices.

The combination of the perforations in the wall of the bowl and screen cloth is used because screen cloth alone would be in capable of withstanding the centrifugal force of the rotating mass of abrasive finishing media. Screen cloth is externally wrapped upon the perforated portion of the wall, rather than lined within the perforated por tion of the wall, subjecting the screen cloth to the abrasive action of the mass of abrasive finishing media.

The mesh size of the screen cloth is selected in accordance with the size and type of abrasive finishing media to be used in a given operation, fine-meshed screen cloth being used with fine grits, and large-meshed screen cloth being used with large chips. In order to accommodate both fine-meshed screen cloth and large-meshed screen cloth, the perforations in the wall are generally of the order of A in diameter or larger.

conventionally, washing liquid, such as a solution of detergent in water, is introduced into the bowl during rotation of the bowl through a spray head or the like. The washing liquid helps to remove the abrasive fines and other waste material. The perforated portion of the bowl permits abrasive particles smaller in size than the perforations to impinge upon the screen cloth and retains the remainder of the charge or mass of abrasive finishing media within the bowl. The screen cloth screens the impinging particles and permits radially outward discharge of abrasive 3,570,184 Patented Mar. 16, 1971 fines and other waste materials. Excess washing liquid is similarly discharged. The mass of abrasive finishing media is replenished from time to time during the operation of the machine to replace abrasive finishing media lost by fragmentation and discharge.

Conventionally, the discharged matter is contained within an outer stationary protective housing and falls to a trough beneath from which it is carried to a drain. The housing also serves to protect the machine operator from injury caused by rotation of the bowl or discharge of matter from the bowl. The housing is capable of being removed or disassembled to give access to the screen cloth and to the steel straps or other holding devices used to hold the screen cloth in place around the perforated portion of the wall of the bowl.

After continued operation of the machine, the meshes of the screen cloth tends to become clogged with abrasive fragments that are too small to be retained by the perforated portion of the wall of the bowl and too large to be discharged through the screen cloth, and the perforation-s in the wall tend to become clogged with abrasive fragments that are too large to pass therethrough. If the meshes of the screen cloth become clogged excessively, the machine must be shut down and the screen cloth temporarily removed for cleaning or replaced. If the perforations in the wall become clogged excessively, the machine must be shut down, the screen cloth temporarily removed, the abrasive finishing media swept away from the wall or temporarily removed from the bowl, and the perforations in the wall cleaned by means of wire brushes or other implements. Furthermore, from time to time, in normal machine maintenance, the screen cloth must be temporarily removed or replaced and the perforations in the wall must be cleaned.

As mentioned, removal or disassembly of the outer stationary protective housing is necessary to give access to the screen cloth and to the steel straps or other holding devices used to hold the screen cloth in place around the ,perforated portions of the wall of the bowl. Usually, the

screen cloth is temporarily removed for cleaning. On one hand, cleaning of screen cloth, particularly small-meshed screen cloth, is usually done with wire brushes and is tedious, but, on the other hand, frequent replacement of screen cloth is needlessly expensive and is not preferred.

Cleaning of the perforations in the lateral wall is difficult and time-consuming. The personnel involved are required to reach over the top edge of the bowl to work with wire brushes or other implements near the bottom of the wall.

This invention is addressed to the alleviation of the problems of machine maintenance alluded to in the foregoing discussion.

SUMMARY OF THE INVENTION It is an object of this invention to provide a rotary finishing machine of the type comprising a rotatable bowl adapted to contain a mass of abrasive finishing media, means for rotating the bowl, and means for turning workpieces in the path of the mass of abrasive finishing media, in which machine cleaning of the screening elements is greatly simplified.

It is another object of this invention to provide a rotary finishing machine, of the aforementioned type, in which the need for screen cloth is eliminated.

It is a more particular object of this invention to provide, in a rotary finishing machine of the aforementioned type, a rotatable bowl comprising a plurality of removable screen panels each of which is provided with a multiplicity of uniform perforations.

Each of the screen panels is positioned to cover one of a plurality of screen openings in the generally cylindrical wall of the bowl. The screen openings extend approximately to the bottom edge of the wall. During rotation of the bowl, centrifugal force serves to hold the screen panels in place against suitable flange means integral with the wall of the bowl at the margins of the screen openings. Thus, the screen panels are supported against radially outward and circumferential displacement with respect to the wall of the bowl. Preferably, fastening means are provided for detachably fastening the screen panels to the flange means.

The screen panels are adapted to screen the mass of abrasive media so as to permit radially outward discharge of abrasive fines and excess washing liquid and retain the remainder of the mass of abrasive finishing media.

These and other objects, features and advantages of this invention are evident in the following description, with the aid of the accompanying drawings, of the presently preferred embodiment of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is an elevational view, partly in section, of a rotary finishing machine embodying the principles of this invention;

FIG. 2 is a sectional view, partly fragmented, taken substantially along section line 22 of FIG. 1 in the direction of the arrows, showing the rotatable bowl of the rotary finishing machine with one of the component screen panels being put in place;

FIG. 3 is a detail view of a fragmentary portion of a screen having fine perforations;

FIG. 4 is a detail view of a fragmentary portion of a screen panel having large perforations; and

FIG. 5 is a detail view on an enlarged scale, in section and fragmented, of exemplary fastening means for detachably fastening the screen panels in place.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, there is illustrated a rotary finishing machine, indicated generally at 10, constituting the presently preferred embodiment of this invention. The rotary finishing machine generally comprises a rotatable bowl 12 adapted to contain a charge or mass of abrasive finishing media 14, means 16 for rotating the bowl 12, means 18 for turning workpieces in the path of the mass of abrasive finishing media 14, and means 20 for introducing washing liquid, such as a solution of detergent in water, into the bowl 12 during rotation of the bowl 12.

The means 16 for rotating the bowl 12 comprises a conventional electric motor 22 and a conventional rightangle speed reducer 24, preferably interconnected by means of a conventional split-sheave variable-speed pulley system, indicated generally at 26, employing a V-belt 28.

The means 18 for turning workpieces in the path of the mass of abrasive finishing media 14 is conventional in rotary finishing machines and comprises a generally cylindrical housing 30 supporting a suitable chuck or collet (not shown) by means of which a variety of workpieces may be held. In FIG. 1, a casting for a bevel gear is shown as an exemplary workpiece to be turned by the means 18. The housing 30 is designed to be swung into and out of the operating position in which it appears in FIG. 1 to permit the machine operator to load and unload the workpieces conveniently. Additional workpiece turning means (not shown), similar to the workpiece turning means 18, may be provided in spaced position around the bowl 12. Owing to the violent dispersion of the mass of abrasive finishing media 14 occurring during operation of the rotary finishing machine 10, it is preferred that no more than three workpieces be finished at one time in the rotary finishing machine 10.

The means 20 for introducing washing liquid, such as a solution of detergent in water, into the bowl 12 during rotation of the bowl 12 comprises a conduit 32 connected to a source (not shown) of washing liquid and a spray head 34 positioned to spray washing liquid onto the workpieces to be turned by the aforementioned workpiece turning means 18. Additional spray heads (not shown) similar to the spray head 34 would be provided if additional workpiece turning means were to be provided as mentioned above.

The rotary finishing machine 10 further generally comprises an outer stationary protective housing 36 which serves to confine matter discharged from the bowl 12 during operation of the machine 10. The housing 36 also serves to protect the machine operator from injury caused by rotation of the bowl 12 or discharge of matter from the bowl 12. The housing 12 defines a trough 38 to which matter discharged from the bowl 12 falls. The trough 38 carries such matter to a drain 40. The housing 36 is designed in multiple interfastened sections (not shown) and is capable of being disassembled to give access to the bowl 12.

The aforementioned bowl rotating means 16, the workpiece turning means 18, the washing liquid introducing means 20, and the outer stationary protective housing 36 are conventional in rotary finishing machines. Further details thereof are outside of the scope of the present disclosure and may be supplied readily by those skilled in the art.

The bowl 12 comprises a generally cylindrical wall 50 and a generally circular bottom 52 integral with the wall 50. In accordance with the principles of this invention, the wall 50 has a plurality of similar spaced screen openings 54, each of which extends approximately to the bottom edge 56 of the wall 50, and the bowl 12 further comprises a plurality of similar removable screen panels 58, each of which is provided with a multiplicity of uniform perforations 60. Each of the screen panels 58 is positioned so as to cover one of the screen openings 54 and is supported, in a manner to be described next, against radially outward and circumferential displacement with respect to the wall 50.

The manner in which the screen panels 58 preferably are supported against radially outward and circumferential displacement with respect to the wall 50 of the bowl 12 is best shown in FIGS. 2 and 5. In FIG. 2, one of the screen panels 58 is shown as being fully in place, another of the screen panels 58 is shown as being put in place, and another of the screen panels 58 is omitted.

In FIGS. 2 and 5, it may be seen that the bowl 12 further comprises flange means 70 for supporting the screen panels 58 against radially outward and circumferential displacement with respect to the screen openings 54. The flange means 70 respectively comprise a first spacer element 72 integral with the wall 50 of the bowl 12 on the outer surface 74 of the wall 50 a short distance removed from one vertical margin 76 of one of the screen openings 54, a first flange member 78 integral with the first spacer element 72 and spaced thereby from the wall 50 so as to define a marginal slot 80 between the first flange member 78 and a portion of the wall 50, a second spacer member 82 integral with the wall 50 on the outer surface 74 of the wall 50 flush with the opposite vertical margin 84 of the same one of the screen openings 54, and a second flange member 86 integral with the second spacer element 82 and spaced thereby from the wall 50 so as to define a marginal recess 88.

In order that the screen panels 58 may be supported flush with the wall 50, the vertical edges 90 of the screen panels 58 which are respectively associated with the firstmentioned vertical margins 76 of the screen openings 54 are provided with integral fiange members 92 on the outer surfaces 94 of the screen panels 58, and the opposite vertical edges 96 are provided with integral spacer members 98 flush therewith on the outer surfaces 94 of the screen panels 58. When the screen panels 58 are properly placed, the flange members 92 fit into the marginal slots 80, the spacer members 98 fit into the marginal recesses 88, and the vertical edges 90 and 96 of the screen panels 58 lie between the vertical margins 76 and 84 of the screen openings 54.

During rotation of the bowl, the centrifugal force of the screen panels 58, augmented by the centrifugal force of the mass of abrasive finishing media 14 serves to hold the screen panels 58 in place against the flange means 70. The flange members 92 on the screen panels 58 bear against the flange members 78 on the wall 50, and the spacer members 98 on the screen panels 58 bear against the flange members 86 on the wall 50. Also, as mentioned above, the vertical edges 90 and 96 of the screen panels 58 lie between the vertical margins 76 and 84 of the screen openings 54. Thus, the screen panels 58 are supported against radially outward and circumferential displacement with respect to the wall 50. It is not necessary to fasten the screen panels 58 to the wall 50. However, in order that a unitary assembly be obtained, it is preferred that suitable fastening means 108 be provided for detachably fastening the screen panels 58 to the flange means 70.

As shown best in FIG. 5, the fastening means 108 comprises respective studs 110 of the type having an enlarged recessed head 112 and an elongated threaded shank 114-. The heads 112 of the respective studs 110 are rotatably recessed within enlarged openings 116 in the screen panels 58 a short distance removed from the second-mentioned vertical margins 96 of the screen panels 58, and the shanks 104 of the respective studs 110 pass through suitable unthreaded openings 118 in the adjacent spacer members 98 and threadably engage suitable threaded openings 120 in the second flange members 86 of the aforementioned flange means 70. Preferably, one such stud 110 is used near the top of each screen panel 58. However, one or more similar studs may be used in addition thereto for each screen panel 58.

Because the studs 110 are installed and de-installed from the inside of the bowl 12, there is no need to disassemble the aforementioned outer stationary protective housing 36 before removing the screen panels 58.

Because the screen panels 58 are installed flush with the wall 50 of the bowl 12, and because the heads 112 of the studs 110 are recessed, as mentioned, the bowl 12 is substantially smooth and free of projections which might interfere with the mass of abrasive finishing media 14. Likewise, the abrasive action of the mass of abrasive finishing media 14 on the screen panels 58 and on the heads 112 of the studs 110 is minimized.

Cleaning of the perforations 60 in the screen panels 58 is greatly simplified by the removal of the screen panels 58. Thus, it is preferred that duplicate sets of similar screen panels be at hand in order that the downtime of the rotary finishing machine thereby might be minimized. If and when the perforations in the screen panels 58 become clogged excessively with abrasive particles that are too large to pass therethrough, the machine 10 is shut down, the mass of abrasive finishing media 14 swept away from the wall 50 or temporarily removed from the bowl 12, and the screen panels 58 removed and replaced by the duplicate screen panels. Thereafter, the removed screen panels 58 may be cleaned while the machine 10 is back in operation.

In the present example, in the lateral wall '50, the screen openings 54 are six in number, four of them appearing in whole or in part in FIG. 1. Accordingly, six screen panels are required for operation of the rotary finishing machine 10. Each of the six screen panels to be used together should have perforations of the same size. However, screen panels having perforations of any practicable size may be used, there being no need for screen cloth or other additional screening elements.

It may be assumed that the perforations 60' in the screen panels 58 of FIGS. 1 and 2 are of the order of A3 in diameter. FIG. 3 illustrates a screen panel 58, interchangeable with any of the screen panels 58. The screen panel 58' is provided with a multiplicity of uniform perforations 60 which may be assumed to be of the order of in diameter. FIG. 4 illustrates a screen panel 58", also interchangeable with any of the screen panels 58. The screen panel 58" is provided with a multiplicity of uniform perforations 60" which may be assumed to be of the order of A in diameter.

The foregoing perforation dimensions are exemplary. Conceivably, screen panels (not shown) having perforations that are smaller than the perforations 60' in the screen panel 58' or larger than the perforations 60" in the screen panel 58" might be used.

Selection is made among screen panels having perforations of various sizes in accordance with the size and type of abrasive media to be used in a given operation, screen panels having small perforations being used with the grits, and screen panels having large perforations being used with large-size chips. The screen panels 5 8 olf1 FIGS. 1 and 2 are used with intermediately sized c ips.

It should be understood that the foregoing description of the presently preferred embodiment of this invention is given solely by 'way of example and that numerous changes within the scope of this invention may be suggested by the present disclosure to those skilled in the art. Accordingly, the scope of this invention should be determined from the following claims.

I claim:

1. A rotary finishing machine comprising, in combination, a rotatable bowl adapted to contain a mass of abrasive media, means for rotating said bowl, and means for turning workpieces in the path of said mass of abrasive finishing media during rotation of said bowl, said bowl comprising a generally cylindrical wall having a plurality of spaced screen openings each of which extends approximately to the bottom edge of said wall, a generally clrcular bottom integral with said wall, and a plurality of removable screen panels each of which is provided with a multiplicity of uniform perforations, each of said screen panels being positioned so as to cover one of said screen openings and being supported against radially outward and circumferential displacement with respect to said Wall, said screen panels being adapted to screen said mass of abrasive media so as to permit radially outward discharge of abrasive tfines and retain .the remainder of said mass of abrasive finishing media.

2. The rotary finishing machine of claim 1 wherein sa d bowl further comprises flange means for supporting said screen panels against radially outward and circumferential displacement with respect to said wall, said flange means being integral with said wall and extending from the margins of said screen openings.

3. The rotary finishing machine of claim 2 wherein said bowl further comprises fastening means for detachably fastening said screen panels to said flange means.

4. The rotary finishing means of claim 1 wherein said screen panels are detachably fastened to said wall.

5. The rotary finishing means of claim 4 wherein said bowl further comprises flange means for supporting said screen panels against radially outward and circumferential displacement with respect to said wall and fastenmg means for detachably fastening said screen panels to said flange means, said flange means being integral with said wall and extending from the margins of said screen openings.

6. The rotary finishing machine of claim 1 further comprising means for introducing washing liquid into said bowl during rotation of said bowl.

7. The rotary finishing machine of claim 6 wherein said bowl further comprises flange means for supporting said screen panels against radially outward and circumferential displacement with respect to said wall, said flange means being integral with said wall and extending from the margins of said screen openings.

8. The rotary finishing machine of claim 7 wherein said bowl further comprises fastening means for detachably fastening said screen panels to said flange means.

9. The rotary finishing means of claim 6 wherein said screen panels are detachably fastened to said wall.

10. The rotary finishing means of claim 9 wherein said bowl further comprises flange means for supporting said screen panels against radially outward and circumferential displacement with respect to said wall and fastening means for detachably fastening said screen panels to said flange means, said flange means being in- 8 tegral with said wall and extending from the margins of said screen openings.

References Cited UNITED STATES PATENTS 3,487,840 1/1970 Stenzel et al 51164X 2,254,219 9/1941 Hamren 5113 FOREIGN PATENTS 509,481 9/1931 Germany 5113 JAMES L. JONES, JR., Primary Examiner US. Cl. X.R. 51164 

